1. Field of the Invention
The invention relates generally to the field of removing a liquid using pressure differentials and gravitational forces. More specifically, the invention relates to the field of removing condensation from confined air conditioning modules, e.g. aircraft air conditioning modules.
2. Description of the Related Art
Air conditioning units are well known in the art, and various methods have heretofore been utilized to drain and dispose the condensate that is generated by air conditioners during cooling cycles. For example, condensate generated by air conditioning units in commercial buildings may be drained using pumps and disposed into rain gutters. Condensate generated by air conditioning units in automobiles may be drained using gravity and disposed on the ground underneath the automobiles via drain tubes.
Air conditioning units used in aircraft may include vapor cycle evaporator drain systems to effectuate drainage of the condensate. FIG. 1 shows an exemplary aircraft air conditioning unit. As can be seen from this figure, the air conditioning unit includes a housing having an angled face, and a drain tube extending from this angled face is used to drain the condensate generated by the unit. If the blower motor is located close to the drain tube, effectiveness of the drain tube during operation of the air conditioning unit is significantly hampered. Specifically, air that is sucked into the unit's housing because of fan suction causes the pressure inside the housing to exceed the ambient pressure, which in-turn prevents the condensate from draining out the drain tube. The condensate thus forms a pool at the floor of the housing, and is often undesirably sprayed out the exhaust, causing damage to the aircraft's interior and inconveniencing the passengers. A common prior art solution to this problem is to locate the blower at an appreciable distance from the evaporator box. However, due to the limited space available in aircraft, this solution is not always feasible.
U.S. Pat. No. 7,543,458 to Wurth is directed to a portable vapor cycling air conditioning unit for use with small aircraft. Wurth ('458) discloses the use of a Venturi drainage system to drain the accumulated condensate. Condensate is conducted from the evaporator via a drain pipe to one or more extraction Venturi tubes that are positioned in a low pressure area in a blower. Forced air from the blower passes over the Venturi tubes and draws the moisture out of the unit. A ducting system is provided to draw air from outside the aircraft and to dispose of condensate and waste heat outside the aircraft.